try:
    total = int(input("输入总课时: "))
    count = int(input("输入课程数: "))

    if total < 100:
        raise ValueError("课时太少")

    time = total / count
    print(f"平均课时: {time}")

except ValueError as e:
    print(f"输入错误: {e}")
except ZeroDivisionError:
    print("错误: 课程数不能为0")
except Exception as e:
    print(f"发生错误: {e}")